JEE · Chemistry · Chemical Kinetics doubts
16 doubts found
What does “Order of reaction” actually mean in Chemical Kinetics, and why does it matter for JEE?
the power to which a reactant's concentration is raised in the experimentally-determined rate law.
I keep getting “Order of reaction” questions wrong in Chemical Kinetics. What's the trap?
reading the order off the balanced equation's coefficients.
What does “Rate constant” actually mean in Chemical Kinetics, and why does it matter for JEE?
the proportionality constant k in the rate law; it rises sharply with temperature.
I keep getting “Rate constant” questions wrong in Chemical Kinetics. What's the trap?
thinking k depends on concentration.
What does “Activation energy” actually mean in Chemical Kinetics, and why does it matter for JEE?
the minimum energy barrier reactants must cross; a catalyst lowers it.
I keep getting “Activation energy” questions wrong in Chemical Kinetics. What's the trap?
thinking a catalyst changes ΔH or the position of equilibrium.
What does “Half-life” actually mean in Chemical Kinetics, and why does it matter for JEE?
the time for a reactant to fall to half its amount; for first-order reactions it's constant.
I keep getting “Half-life” questions wrong in Chemical Kinetics. What's the trap?
assuming half-life is constant for every order.
What is the difference between order and molecularity?
Order is experimental and can be zero or fractional; molecularity is the count of species in an elementary step and is always a whole number.
What is the difference between rate and rate constant?
Rate depends on concentration and changes as the reaction proceeds; the rate constant k is fixed at a given temperature.
What is the difference between catalyst on rate and catalyst on equilibrium?
A catalyst speeds a reaction by lowering activation energy but does NOT shift the equilibrium position.
When do I use k = A·e^(−Ea/RT) in Chemical Kinetics, and what does it mean?
Arrhenius equation linking rate constant to temperature.
When do I use t½ = 0.693/k in Chemical Kinetics, and what does it mean?
half-life of a first-order reaction.
How is Chemical Kinetics tested in JEE, and what should I focus on?
Prioritise the core ideas: Order of reaction, Rate constant, Activation energy.
What are the most common mistakes students make in Chemical Kinetics?
order is found by experiment; it only matches the coefficients for a genuinely elementary reaction.
How do I revise Chemical Kinetics quickly before the exam?
One-page summary of Order of reaction, Rate constant, Activation energy, then timed previous-year questions.